1. Field of the Invention
The present invention relates to a work vehicle having an engine, a PTO shaft driven by power from the engine, an operator's seat, an operator's presence sensor for detecting presence/absence of an operator at the operator's seat, and an automatic engine stop unit for automatically stopping the engine in response to detection of absence of the operator at the operator's seat.
2. Description of the Related Art
Conventionally, with a work vehicle such as a tractor, a mowing machine, etc., when an operator leaves the operator's seat, a traveling of the vehicle body or driving of an implement connected to the PTO output shaft with the power from the engine is inhibited by the automatic engine stop unit operable to automatically stop the engine in response to detection of absence of the operator at the operator's seat (the operator's leaving the seat).
On the other hand, it is sometimes necessary for the work vehicle to carry out a stationary work such as an irrigating work or a wood chopping work by driving a pump for irrigation or a wood chopper connected to the PTO shaft with the power from the engine. For carrying out such stationary work not requiring traveling of the vehicle body, an operator needs to remain seated at the operator's seat in order to maintain the operator's presence sensor under its presence detecting state. This has been inconvenient. Addressing to this inconvenience, there is known from e.g. Japanese Patent Application “Kokai” No.: Hei. 01-155037 or U.S. Pat. No. 5,203,440, a system operable not to stop the engine under a certain predetermined transmission condition of the vehicle for allowing the engine to drive the PTO shaft under such condition. However, as such predetermined vehicle transmission condition varies according to the type of work to be effected, it has been difficult to specify a particular vehicle transmission condition which is relatively universally applicable to various situations.